Releasable supporting apparatus

ABSTRACT

Apparatus is disclosed for releasably suspending a condition measuring device, such as a weighted or sinker thermocouple, above a steel-refining vessel. The apparatus includes a fusible link, the fusing of which acts to release the device whereby it drops into the vessel. The electrical lead wire of the measuring device is arranged in a controlled bundle for ease of handling and for insuring the smooth pay-off of the wire as the device drops.

United States Patent Stawarski et al.

July 4, 1972 RELEASABLE SUPPORTING APPARATUS Inventors:

Chester C. Stawarski, 388 Pinehaven Drive, Bethel Park, Pa. 15102;Charles C. Gerding, 728 Gaywood Drive; Richard T. Adams, 149 RoseAvenue. both of Penn Hills, Pa l5235 Filed: Sept. 1, I970 Appl. No.:68,778

Related US. Application Data Continuation-impart of Ser. No. 836,687,June 2,

1969, abandoned.

U.S. Cl. ..73/343 R, 73/359 Int. Cl ..G0lk 1/14, GOlk [3/00 Field ofSearch ..73/359;248/320, 322,5;

52/232, l; l69/42; l26/287.5;73/343, 170

Primary Examiner-Louis R. Prince Assistant ExaminerDenis E. CorrAttorney-T. A. Zalenski and G. R. Harris 57 ABSTRACT Apparatus isdisclosed for releasably suspending a condition measuring device, suchas a weighted or sinker thermocouple, above a steel-refining vessel Theapparatus includes a fusible link, the fusing of which acts to releasethe device whereby it drops into the vessel. The electrical lead wire ofthe measuring device is arranged in a controlled bundle for ease ofhandling and for insuring the smooth pay-off of the wire as the devicedrops.

FATENTEUJUL 4 I972 SHEEI 1 If 2 INVENTORS. CHESTER C. STAWARSKI CHARLESC.GERDING BY RICHARD T. ADAMS fld ATTORNEY FATENTEDJJL 415?: $673,869

SHEET 20F 2 ELECTRICAL 48 POWER SOURCE ELECTRICAL POWER SOURCEiNVENTORS.

CHESTER C. STAWARSKI CHARLES CJGERDNG RICHARD TADAMS ff/WA ATTORNEYRELEASABLE SUPPORTING APPARATUS This application is acontinuation-in-part of our application Ser. No. 836,687, filed June 2,1969, now abandoned.

This invention relates to apparatus, including a link, breakable uponthe application of electrical power thereto, comprising a releasablesupport. The invention relates particularly to apparatus for supportingand selectively releasing a sinker thermocouple, having its lead wirearranged in a controlled bundle, into a basic oxygen furnace to measurethe temperature of the molten steel contained therein.

For controlling the course of refining of a basic oxygen steelmakingprocess, as well as for other reasons, it is important to know thetemperature of the molten bath at various times during the refiningcycle. Weighted or sinker thermocouples of the type disclosed in U.S.Pat. No. 3,347 ,099 are particularly useful for this purpose since theiruse does not require the vessel to be turned down in order that itsmouth be accessible from the operating platform.

Sinker thermocouples can be injected into a basic oxygen steelmakingvessel by, for example, pitching the thermocouples up over the lip ofthe vessel or having a workman drop them from above the vessel throughan opening in the wastegas hood covering the mouth of the vessel. Thefirst method is not reliable and it is not, in either method, convenientor desirable to station a workman near the mouth of the vessel duringthe refining cycle to inject the thermocouples therein. In addition,because these and other methods require manual assistance at or near themoufli of the vessel, some signalling means from the furnace controlroom is also required.

Thus, a need exists for apparatus for automatically introducing sinkerthermocouples into a basic oxygen steelmaking furnace, apparatus whichis reliable in the demanding environment of a basic oxygen shop.Accordingly, it is an object of our invention to provide such apparatus,including a fusible link and associated means for fusing the link torelease the sinker thennocouple into the furnace. Another object of ourinvention is to provide such apparatus wherein the thermocouple issuspended from the fusible link which in turn is suspended from a pairof electrodes connected to a source of electrical power. Yet anotherobject of our invention is to provide such apparatus wherein thethermocouple is supported by means adapted for movement from a firstposition supporting said device to a second position releasing it, thefusible link maintaining said means in the first position and fusing ofthe link allowing said means to move to the second position. Stillanother object of our invention is to provide the electrical lead wireof the thermocouple in a compact bundle for ease of handling thethermocouple and for ease of loading it onto the apparatus and forinsuring the smooth pay-off of the wire as the thermocouple drops.

These and other objects and advantages of our invention will be moreapparent from the following detailed description thereof with referenceto the accompanying drawings in which:

FIG. I is a front-elevational view of a first embodiment of theinvention, in which the circular coil of wire is shown in section;

FIG. 2 is a fragmentary, reduced, side-elevational view of the firstembodiment of the invention;

FIG. 3 is a fragmentary, front-elevations] view of a second embodimentof the invention; and

FIG. 4 is a fragmentary, side-elevational view of the second embodimentof the invention.

Typically, a plurality of the releasable supporting mechanisms shown inthe drawings are arranged in a row at the top of a funnel-shaped chute,about to 30 feet above a molten metal bath. The bottom of the chuteextends through the waste-gas hood covering the mouth of a basic oxygensteelmaking vessel containing the molten metal, whereby thethermocouples associated with the mechanisms, upon their release intothe chute, pass into the vessel.

According to a first embodiment of the invention, the means forreleasably supporting a sinker thermocouple l0 and the electrical leadwire associated with it includes fusible link 11, comprising, forexample, 0.018! inch diameter steel wire, and a rotating means,indicated generally at 12. The rotating means comprises a first rodmember 13 mounted in openings in brackets 14-14 for rotation thereinabout its longitudinal axis. The brackets are mounted on a stationarysupport plate 15. A second rod member 16 integral with rod member 13 andextending transversely thereof has at one end a crook 17 from whichsinker thermocouple 10 is suspended. A weight 18 integral with the firstand second rod members is located along the longitudinal axis of rodmember 13 in a position such that when the rotating means is in itssuspending position, as shown in FIG. 1, the center of gravity of therotating means is on the same side of the longitudinal axis of rodmember 13 as crook l4 and sinker thermocouple 10. The rotating means iscounterbalanced and maintained in this position by fusible link 11 whichis looped over rod member 16 on the side of the longitudinal axis of rodmember 13 opposite that of crook l4 and sinker thermocouple 10. Each endof the fusible link is firmly attached to electrically conductive pinsl9l9 mounted in block 20 made of electrical insulating material andmounted on support plate 15.

The electrically conductive pins are connected by suitable electricallead wires, not shown, to a source of electrical power which ispreferably located at some remote spot, such as the operating floor.When it is desired to measure the temperature of the molten metal withinthe vessel, electrical energy from the source is applied to the fusiblelink causing the link to fuse, freeing rotating means 12 for rotation tothe position shown in phantom lines in FIG. 2, thereby dropping thethermocouple into the vessel.

In the apparatus of the invention, the electrically fusible link 1 1comprises any wire element whose ability to bear tension is destroyed bythe passage therethrough of an electrical current of suitable magnitude.We have observed that such an electrical current has several destructiveeffects on the wire. These are, the heating of the wire to its fusionpoint, the heating of the wire to a temperature where it softens, and,to some extent, surface oxidation of the wire. The relative magnitudesof these effects in the destruction of a particular wire depend, amongother variables, on the electrical current, the tension in the wire, therate of temperature rise of the wire, and the wire cross-section. From apractical standpoint, the exact mode of failure of the wires is notsignificant. What is important is that for a particular wire employed, areasonable current and voltage drop results in the failure of the wirewithin 5 seconds under the tension imparted by the weight of thethermocouple. For example, a No. 26 gage annealed, carbon-steel wirefails in substantially less than 5 seconds when a voltage drop of 30volts per inch is applied across the wire.

To prevent the electrical lead wire associated with the thermocouple 10from tangling as the thermocouple drops into the vessel and to provide acompact bundle which can be conveniently handled, the wire is arrangedin three concentric spirally-wound cylindrical layers 26, 27 and 28. Theinnermost layer of wire 26 terminates in a first free end-length 25 oflead wire which is electrically connected to thermocouple N). Theoutermost layer of lead wire 28 terminates in a second free end-length2A of lead wire and is adapted to be connected to a temperature recorderfor recording the temperature of the molten metal within the vessel.Preferably, the recorder is located adjacent the electrical power sourcefor fusible link 11; and end-length 24 of the lead wire is connected toan intermediate station adjacent rotating means 12, which station is inturn permanently connected to the recorder through compensatingcircuitry as described, for example, in U.S. Pat. No. 3,347,099.

The layers of the lead wire bundle are held in place and the integrityof the bundle maintained while the thermocouple is in its supportedposiu'on by a number of tear-tape strips breakable upon application of asudden jerking force. Each lead wire layer is joined by the tape stripsto all layers lying inside of it. First tape strips 29-29 longitudinallyencircle outer layer 28; second tape strips 30-30 longitudinallyencircle outer layer 28 and middle layer 27; and third tape strips 31-31 longitudinally encircle outer layer 28, middle layer 27 and innerlayer 26.

A wire ring 35 is clamped to end-length 25 of lead wire at a pointadjacent thermocouple by a means of a depending portion 36 and thethennocouple unit suspended on crook 17 by the ring. The weight of thethermocouple is thus transferred to the supporting mechanism throughring 35 and no strain is placed on the wire bundle as would be the caseif the sinker were suspended merely by looping the wire over the crook17.

A wire mounting bracket 37 is clamped by means of depending portions38-38 to the last convolution of the outermost layer 28 of the spirallywound wire bundle, that is, substantially at the location where thelayer terminates into free end-length of wire 24. The bracket includes apair of mounting rings 3939 through which positioning rod 40 is insertedwhen thermocouple 10 is loaded onto rotating means 12. Rod 40 issupported by stationary support member 41 and 42.

When a temperature measurement of the molten metal within the vessel isto be made, the electrical power source is activated and resultingelectrical energy flowing through fusible link 1 l, fuses the linkwhereupon rotating means 12 rotates to its releasing position as shownin phantom lines in FIG. 2. As this occurs, ring 35 becomes free ofcrook l7 and sinker thermocouple l0 begins to fall, extending the freeendlength of lead wire. Thereafter, the force of the falling sinkerthermocouple snaps tapes 3l3l. The innermost layer of wire 26 then paysoff until it is expended whereupon tapes 30 snap and the middle layer ofwire 27 pays off until it is expended; then tape strips 29-29 aresnapped and the outermost layer of wire 28 pays off; by this time thesinker thermocouple has entered the molten metal in the vessel. The tapestrips are arranged so that except for the last layer to play out eachlayer is attached to one of the layers which plays out after it. Theteartape strips thus act as means for causing the layers of lead wire tosuccessively play out upon release of the sinker thermocouple.

As the thermocouple falls, bracket 37 maintains the bundle of lead wirein an anchored position allowing each successive layer of the bundle topay off in an orderly fashion. In addition, if it is desired to stop thethermocouple at a particular level above the bottom of the vessel, alesser length of lead wire is used between the sinker and the bracketand the thermocouple is arrested as it settles in the molten bath whenthe lead wire has been extended to the point where it is attached to thebracket. We find that a certain amount of plastic bending of the bracketoccurs when the thermocouple is dropped and regard this as desirable inthat the falling wire is thus dccelerated without undue stress.

To reload the releasing apparatus, rod is withdrawn from its supports 4!and 42, bracket 37 and associated expended lead wire from the previouslyreleased thermocouple mechanism are removed from the rod and disposed ofby being dropped into the furnace and a fresh thermocouple mechanismmounted onto rod 40 by means of its mounting bracket 37.

In the embodiment of the invention illustrated in FIGS. 3 and 4, meansfor supporting the thermocouple mechanism in a suspended positionincludes a pair of electrodes 45-45 mounted in a block of electricalinsulating material 46 which is supported by fixed support 47. Thethermocouple is suspended from electrodes 4545 by means of a loop offusible wire 49 which is in electrical contact with the electrodes andis attached to the thermocouple through ring 35. As described above, thering is clamped to the electrical lead wire 25 by means of its dependingportion 36. Alternates, the loop of wire 49 is made longer and twisteddirectly about lead wire 25, eliminating ring 35 and depending element36.

A wire bracket is clamped to wire bundle 52 at its last convolution bymeans of depending portions 5l5l. The wire bundle is formed in themanner as described above. Wire bracket includes a pair of mountingrings 5353 which are placed over vertical mounting pins 54-54 secured tosuitable fixed supports.

By activating electrical power source 48 associated with fusible link49, electrical energy flows through the link fusing it and allowing thesinker thermocouple to fall. As the thermocouple falls, wire bundle 51pays off in the manner described above. A fresh thermocouple is loadedsimply by looping a fusible link associated with a thermocouplemechanism over electrodes 45-45 and mounting the thermocouple mechanisms support bracket 50 over pins 54-54.

We claim:

1. Apparatus for releasably supporting a device in a suspended positioncomprising rotating means mounted for movement about an axis of rotationfrom a first position carrying said device to a second positionreleasing said device, a link breakable upon the application ofelectrical power thereto being attached to said rotating means tomaintain the rotating means in said first position, means associatedwith said link for causing failure of the link as desired, such failureof said link allowing said rotating means to move to said secondposition.

2. The apparatus of claim 1 wherein said rotating means when in saidfirst position has a center of gravity spaced to one side of said axisof rotation, said link being attached to the rotating means at alocation spaced to the other side of said axis of rotation.

3. The apparatus of claim 1 wherein said rotating means includes a firstrod member having a crook at one end thereof, a second rod memberintegral with said first rod member and extending transversely thereof,said second rod member being mounted within brackets for rotativemovement about its longitudinal axis, and a weight integral with saidfirst rod member and positioned thereon so as to be on the same side ofthe first rod member as said crook with relation to the longitudinalaxis of the second rod member when the supporting means is in said firstposition, and said link comprising a wire fastened at both ends toelectrically conductive pins and looped over the first rod member on theside thereof with relation to the longitudinal axis of the second rodmember opposite from the weight when the supporting means is in saidfirst position.

4. Means including a link breakable upon the application of electricalpower thereto supporting a device in a suspended position for selectiverelease, and means associated with said link for causing failure of thelink as desired releasing said device from its suspended position, saidsupporting means including a pair of spaced electrodes and said linkcomprising a loop of fusible wire suspended from said electrodes, saiddevice being suspended from said link.

5. The apparatus of claim 4 wherein said device includes an extendedlength of electrical lead wire arranged in a compact bundle and bracketmeans clamped to said lead wire and attached to a stationary support,thereby anchoring said lead wire thereat.

6. The apparatus of claim 5 wherein the compact bundle of lead wirecomprises a plurality of spirally wound concentric layers of lead wire,each layer being joined to all layers lying inside of it by meansbreakable upon application of a sudden jerking force.

7. Apparatus for developing and transmitting an electrical signal inresponse to a condition in a molten metal bath comprising a conditionmeasuring device and a length of electrical lead wire arranged in acompact bundle comprising a plurality of spirally wound concentriclayers of lead wire, there being innermost and outermost layers of leadwire, the innermost layer of lead wire terminating in a first freeend-length of lead wire, the outermost layer of lead wire terminating ina second free end-length of lead wire, said condition measuring devicebeing electrically connected to one of said free end-lengths of leadwire, means attached to said bundle of lead wire causing said pluralityof layers to successively play out upon release of said conditionmeasuring device from a suspended position, and bracket means forpositioning the apparatus on a fixed support clamped to one of theinnermost and outer-most layers of lead wire substantially at thelocation where it terminates into a free end-length of lead wire.

consisting of three spirally wound concentric layers of lead wire, saidthennocouple being electrically connected to said first free end-lengthof lead wire, and said means releasable upon the application of a suddenjerking force comprises first tape strips longitudinally encircling theoutennost layer, second tape strips longitudinally encircling only themiddle and outermost layers and third tape strips longitudinallyencircling all three layers.

i i i i i

1. Apparatus for releasably supporting a device in a suspended position comprising rotating means mounted for movement about an axis of rotation from a first position carrying said device to a second position releasing said device, a link breakable upon the application of electrical power thereto being attached to said rotating means to maintain the rotating means in said first position, means associated with said link for causing failure of the link as desired, such failure of said link allowing said rotating means to move to said second position.
 2. The apparatus of claim 1 wherein said rotating means when in said first position has a center of gravity spaced to one side of said axis of rotation, said link being attached to the rotating means at a location spaced to the other side of said axis of rotation.
 3. The apparatus of claim 1 wherein said rotating means includes a first rod member having a crook at one end thereof, a second rod member integral with said first rod member and extending transversely thereof, said second rod member being mounted within brackets for rotative movement about its longitudinal axis, and a weight integral with said first rod member and positioned thereon so as to be on the same side of the first rod member as said crook with relation to the longitudinal axis of the second rod member when the supporting means is in said first position, and said link comprising a wire fastened at both ends to electrically conductive pins and looped over the first rod member on the side thereof with relation to the longitudinal axis of the second rod member opposite from the weight when the supporting means is in said first position.
 4. Means including a link breakable upon the application of electrical power thereto supporting a device in a suspended position for selective release, and means associated with said link for causing failure of the link as desired releasing said device from its suspended position, said supporting means including a pair of spaced electrodes and said link comprising a loop of fusible wire suspended from said electrodes, said device being suspended from said link.
 5. The apparatus of claim 4 wherein said device includes an extended length of electrical lead wire arranged in a compact bundle and bracket means clamped to said lead wire and attached to a stationary support, thereby anchoring said lead wire thereat.
 6. The apparatus of claim 5 wherein the compact bundle of lead wire comprises a plurality of spirally wound concentric layers of lead wire, each layer being joined to all layers lying inside of it by means breakable upon application of a sudden jerking force.
 7. Apparatus for developing and transmitting an electrical signal in response to a condition in a molten metal bath comprising a condition measuring device and a length of electrical lead wire arranged in a compact bundle comprising a plurality of spirally wound concentric layers of lead wire, there being innermost and outermost layers of lead wire, the innermost layer of lead wire terminating in a first free end-length of lead wire, the outermost layer of lead wire terminating in a second free end-length of lead wire, said condition measuring device being electrically connected to one of said free end-lengths of lead wire, means attached to said bundle of lead wire causing said plurality of layers to successively play out upon release of said condition measuring device from a suspended position, and bracket means for positioning the apparatus on a fixed support clamped to one of the innermost and outermost layers of lead wire substantially at the location where it terminates into a free end-length of lead wire.
 8. The apparatus of claim 7 wherein said means attached to said bundle of lead wire comprises means releasable upon application of a sudden jerking force, said releasable means joining each layer of lead wire to all layers of lead wire which play out after it upon release of the condition measuring device from a suspended position.
 9. The apparatus of claim 8 wherein the condition measuring device comprises a sinker thermocouple for measuring the temperature of the molten metal bath, said bundle of lead wire consisting of three spirally wound concentric layers of lead wire, said thermocouple being electrically connected to said first free end-length of lead wire, and said means releasable upon the application of a sudden jerking force comprises first tape strips longitudinally encircling the outermost layer, second tape strips longitudinally encircling only the middle and outermost layers and third tape strips longitudinally encircling all three layers. 